Abdelhameed Ali S, Alam Parvez, Khan Rizwan Hasan
a Department of Pharmaceutical Chemistry, College of Pharmacy , King Saud University , Riyadh 11451 , Saudi Arabia.
b Interdisciplinary Biotechnology Unit , Aligarh Muslim University , Aligarh 202002 , India.
J Biomol Struct Dyn. 2016 Sep;34(9):2037-44. doi: 10.1080/07391102.2015.1104522. Epub 2016 May 9.
In this report, we have investigated the binding affinity of tofacitinib with human serum albumin (HSA) under simulated physiological conditions by using UV-visible spectroscopy, fluorescence quenching measurements, dynamic light scattering (DLS), differential scanning calorimetry (DSC) and molecular docking methods. The obtained results demonstrate that fluorescence intensity of HSA gets quenched by tofacitinib and quenching occurs in static manner. Binding parameters calculated from modified Stern-Volmer equation shows that the drug binds to HSA with a binding constant in the order of 10(5). Synchronous fluorescence data deciphered the change in the microenvironment of tryptophan residue in HSA. UV spectroscopy and DLS measurements deciphered complex formation and reduction in hydrodynamic radii of the protein, respectively. Further DSC results show that tofacitinib increases the thermo stability of HSA. Hydrogen bonding and hydrophobic interaction are the main binding forces between HSA and tofacitinib as revealed by docking results.
在本报告中，我们运用紫外可见光谱、荧光猝灭测量、动态光散射（DLS）、差示扫描量热法（DSC）和分子对接方法，研究了托法替布在模拟生理条件下与人血清白蛋白（HSA）的结合亲和力。所得结果表明，托法替布使HSA的荧光强度猝灭，且猝灭以静态方式发生。根据修正的斯特恩-沃尔默方程计算的结合参数表明，该药物与HSA结合的结合常数约为10⁵。同步荧光数据解析了HSA中色氨酸残基微环境的变化。紫外光谱和DLS测量分别解析了复合物的形成以及蛋白质流体力学半径的减小。进一步的DSC结果表明，托法替布提高了HSA的热稳定性。对接结果显示，氢键和疏水相互作用是HSA与托法替布之间的主要结合力。
